尿中二甲苯3种代谢产物测定的固相萃取-液质联用法

Detection of three metabolites of xylene in urine samples by solid-phase extraction coupled with liquid chromatography-mass spectrometry

目的:建立超高效液相色谱-高分辨质谱(UPLC-HRMS)快速检测职业暴露工人尿液中二甲苯的3种代谢产物2-甲基马尿酸、3-甲基马尿酸和4-甲基马尿酸含量的方法。方法:于2022年7月,尿液样品经pH=6.86磷酸缓冲液稀释与提取,经MAX固相萃取柱净化后,采用Accucore Ph/Hexyl色谱柱(100 mm×2.1 mm,2.6μm),以5 mmol/L甲酸铵-0.1%甲酸水溶液和甲醇为流动相梯度洗脱,采用电喷雾负离子模式和一级全扫描-数据依赖二级质谱扫描模式进行分析,外标法定量,分析方法的各指标特征。结果:2-甲基马尿酸、3-甲基马尿酸和4-甲基马尿酸在1.0~200.0μg/L浓度范围内呈现良好的线性关系,相关系数0.9979~0.9993;方法检出限为0.18~0.24μg/L;低、中、高(1.0、100.0和180.0μg/L)3个浓度下的加标回收率为83.0%~93.7%,相对标准偏差为2.2%~7.9%。结论:UPLC-HRMS法简便、快速、灵敏和准确,适用于职业暴露工人尿液中二甲苯3种代谢产物的同时测定。

Objective To establish a method for the rapid determination of the three metabolites of xylene,2-methylmarmaluronic acid,3-methylmarmaluronic acid and 4-methylmarmaluronic acid,in urine of occupationally exposed workers by ultra-performance liquid chromatography-high resolution mass spectrometry(UPLC-HRMS).Methods In July 2022,urine samples were diluted and extracted with pH=6.86 phosphate cache solution,cleaned up by a MAX solid-phase extraction(SPE)column and separated by an Accucore Ph/Hexyl column(100 mm×2.1 mm,2.6μm)with a gradient of 5 mmol/L ammonium formate-0.1%formic acid aqueous solution and methanol as mobile phases.The analysis was carried out in electrospray ionization mode and full mass-data dependent secondary mass spectrometry mode,and quantified by external standard method.The characteristics of each index of this method were analyzed.Results A good linearity was obtained in the concentration range of 1.0-200.0μg/L for 2-methylmuramic acid,3-methylmuramic acid and 4-methylmuramic acid with the correlation coefficients of 0.9979-0.9993.The limits of detection of the method were 0.18-0.24μg/L.While the spiked recoveries at the three concentrations(1.0μg/L,100.0μg/L,and 180.0μg/L)were in the range of 83.0%-93.7%,with the relative standard deviations of 2.2%-7.9%.Conclusion The UPLC-HRMS method is simple,rapid,sensitive and accurate,and is suitable for the simultaneous determination of the three metabolites of xylene in the urine of occupationally exposed workers.